.\" This manual was prepared by United States Government employees 
.\" as part of their official duties and is, therefore, a work of the
.\" U.S. Government and not subject to copyright.
.\"
.\" $Id: fedex.1,v 2.1.0.2 1998/02/27 23:54:30 sauderd Exp $
.TH FEDEX 1 "12 June 1995"
.SH NAME
fedex \- EXPRESS Compiler
.SH SYNOPSIS
.B fedex
[
.BI \-e " Express-schema-file"
]
[
.BI \-w " warning-class\fR \.\|.\|. ]"
[
.BI \-i " warning-class\fR \.\|.\|. ]"
.SH DESCRIPTION
fedex is an EXPRESS-based translator.  It parses the EXPRESS language
information model contained in the input EXPRESS file and sends
warnings and errors to stdout.
.LP
The 
.RB ` "\-w \fIwarning-class\fP" '
and 
.RB ` "\-i \fIwarning-class\fP" '
options are used to enable or disable various categories of warning
messages.  These options are processed left-to-right, with later
options overriding earlier ones.  Any number of these options may
appear in any order.
.LP
During the parsing of the EXPRESS file,
.B fedex 
detects any problems with the input schema.  These problems are
reported to the user, subject to the controls imposed by any
.RB ` \-w '
and 
.RB ` \-i '
options.
If no errors are encountered, 
.B fedex
terminates with an appropriate message.
.SH OPTIONS
To see a list of options, run fedex without any arguments.
.SH SEE ALSO
.LP
.I
\The NIST EXPRESS Working Form,
\NISTIR 4814, Clark, S., and Libes, D., revised, April 1992.
.LP
ISO 10303-11:1994 
.I 
\Industrial Automation Systems and Integration -- Product Data \
Representation and Exchange -- Part 11: Description Methods: The \
EXPRESS Language Reference Manual.
.LP
.I 
\The NIST EXPRESS Toolkit - Design and Implementation, \
Engineering Data Management: Key to Success in a Global Market, \
Proc. of the 1993 ASME Intl. Computers in Engineering Conference,
August 8-12, 1993, San Diego, pp. 167-180.
.LP
.I
\The NIST EXPRESS Toolkit: Using Applications,
\NISTIR 5206, Libes, D., June 1993.
.LP
.I
\Fed-X: The NIST EXPRESS Translator,
\NISTIR 4822, Libes, D., April 1992.

.SH BUGS

Some Express language constructs are accepted by fedex but are not
represented in the Express Working Form, and so are not available
during the output pass.  These constructs include cardinality
expressions, MAP directives, and supertype expressions.  In addition,
PRIVATE directives and WITH statements are represented in the Working
Form, but are ignored during symbol lookup.  This may produce spurious
warnings about undefined or multiply defined identifiers.
.LP
According to the rules of EXPRESS (STEP Part 11, Section 9.2.4.5), the
AND operator has a higher precedence than ANDOR.  fedex considers them
to have an equal level of precedence and processes them from left to
right.  A work around would be to use paretheses around all AND
operators appearing in an expression.
.LP
Expressions are not `type'd properly: although an expression's type
can be derived from its components, this has not been implemented.
This can result in spurious warnings.  A notable example occurs when a
complex expression used as a loop control (WHILE or UNTIL) does not
appear to compute a boolean result simply because no type has been
computed for the expression.

.SH NOTE
.LP

All NISTIR documents may be obtained through the National Technical
Information Service (NTIS), Springfield VA 22161, USA.  Postscript
files may be obtained from the STEP Class Library web page
(http://www.nist.gov/scl), the Manufacturing Systems Integration
Division publications page
(http://www.mel.nist.gov/msidlibrary/pubs.htm) or by anonymous ftp
from ftp.cme.nist.gov (see
pub/subject/sc4/national/usa/nist/docs/readme.txt to determine the
appropriate file to download).
